Maintaining a diverse population of prey in an urban landscape is necessary to attract and support sustainable populations of predators and parasitoids. This relationship is fundamental to the implementation of conservation biological control. The modern urban landscape is dominated by alien ornamentals; these plants are unacceptable hosts for many of the specialist herbivores that evolved to be dependent on native plants. Alien dominated landscapes may therefore host a less diverse prey population for natural enemies. We predict that landscapes that are dominated by native plants host a diverse herbivore population that will attract and sustain a diverse population of predators and parasitoids relative to landscapes dominated by alien plants. Two types of ‘urban’ landscapes were planted to test this prediction; one dominated by native ornamentals and another dominated by alien ornamentals. The plants within the native and alien landscapes were sampled twice during the growing season to quantify the density and diversity of their herbivore and natural enemy populations. The results of this study will provide data on the role of native plants for conservation biological control in landscapes and may provide a new tool for pest management in the expanding urban environment.